A facile colloidal solution method has been developed for the fast, scalable synthesis of orthorhombic@cubic core–shell nonstoichiometric Cu 5FeS 4 icosahedral nanoparticles. Such nanoparticles contain high-density twin boundaries in the form of fivefold twins. Spark plasma sintering consolidates the nanoparticles into nanostructured pellets, which retain high-density twin boundaries and a tuned fraction of the secondary phase Fe-deficient cubic Cu 5FeS 4. As a result, the thermal and electrical transport properties are synergistically optimized, leading to an enhanced zT of ≈0.62 at 710 K, which is about 51% higher than that of single-phase Cu 5FeS 4. This study provides an energy-efficient approach to realize twin engineering in nonstoichiometric Cu 5FeS 4 nanomaterials for high-performance thermoelectrics.
- Cu FeS
- twin engineering
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics